Oral or Poster Presentation
Concurrent Session 4A - Perinatal Epidemiology
Introduction: Approximately 8-13% of pregnant women have asthma, with 50% experiencing sub-optimal asthma control during pregnancy, potentially due to medication poor-adherence. With different safety profiles and risk perception of medication use during pregnancy, the objective of this study is to assess whether adherence pattern for pregnant women with asthma differs by drug class.
Methods: Pregnant women with asthma in Alberta, Canada were identified in the administrative databases (≥1 diagnosis of asthma in the hospitalization, emergency department visits, and outpatient physician’s office visits data or two prescriptions of short-acting-beta-agonist from community pharmacies) (2012-2016). Women adherent to their asthma medications one-year prior to pregnancy, determined using a prescription-based medication possession ratio of ≥0.8, were included in the present study. Chi-square tests were conducted to assess if medication adherence in the year prior to and during pregnancy differed by drug class (inhaled corticosteroids (ICS), ICS + long-acting-beta-agonist (LABA)).
Results: Overall, 20,977/159,059 (13.18%; 95% CI: 13.02-13.36%) of pregnant women had asthma. In the year prior to pregnancy, women with prescription for ICS+LABA were more likely to be adherent (71.81%; 95% CI: 66.74-76.38%) than women on ICS alone (28.19%; 95% CI: 23.62-33.26%) (p=0.03). Of the women who were adherent prior to pregnancy, 43.03% (95% CI: 37.81-48.40%) were poorly adherent and 27.30% (95% CI: 22.79-32.33%) discontinued their medications during pregnancy. Medication adherence differed by drug class during pregnancy (p=0.003), with 84.00% (95% CI: 75.29-90.04%) of women on ICS+LABA and 16.00% (95% CI: 9.96-24.71%) of women on ICS being adherent during pregnancy.
Conclusion: A substantial proportion of women with asthma were poorly adherent to their asthma medications before and during pregnancy. Women with ICS were less likely to be adherent one year prior to and during pregnancy. Poor adherence to asthma medication, even amongst women who were adherent prior to pregnancy, may place pregnant women at increased risk of poorly-controlled asthma.